In satellite communication, a mobile terminal is required for communication services such as voice, data, Internet access, remote control, video conferencing, video streaming, and so forth. Such a terminal is preferably small enough to be portable, be able to support a reasonably high data rate, be easy to set-up, and conforms to the general regulations relating to satellite transmissions.
Present products address the requirement of portability by using a smaller antenna (typically a dish antenna 1.8 m in diameter for C-Band satellite communication) but thereby compromise the quality of the link. The design of small size antenna for any given frequency band become quite difficult because the level of interference and system noise become unacceptable when the antenna is small, and it will be difficult to conform to the regulations relating to satellite transmission. For example: for the C-Band frequency band, the smallest practical antenna presently available is a 1.8 m diameter dish antenna. This sets the limits on the size and weight of the terminal system.
When the terminal is being stowed, a typical antenna will need to be disassembled and placed in a number of boxes. The combined weight is quite heavy. For a 1.8 m diameter C-band antenna, it is typically in the region of 100 kg. In certain low data rate applications, where the terminal size is more important than data rate, a smaller antenna is used. However, the antenna gain is compromised. To compensate for the lower antenna gain, a higher power transceiver is employed. Such transceivers are more expensive, heavier, and have a higher power consumption. When higher power transmission is used with a small antenna, it may violate the off-axis emission regulations.
Some products attempt to satisfy the requirement for a reasonably high data rate by increasing antenna size, thus compromising the other two requirements (being portable, and easy to set-up). This makes the terminal even heavier. Normally, it needs at least two people to set up the terminal, and the setup may take longer time.
Although there is significant interest in the use of communication satellites for mobile application, the limitations in providing a truly portable satellite terminal that can provide good quality services has not thus far been able to be overcome. Therefore, there is a significant need for a portable terminal that is compact, easy to set-up, and provides a reasonably high data rate